Automotive trim maker cuts £10k off energy bill

R-Tek, a US-based manufacturer of automotive trim for Nissan is using variable speed drives from ABB to help cut its energy bill by £10,000 per year. The company produces injection moulded automotive trim components and, as part of a cost reduction programme, has been considering ways of making its injection moulding machines more energy efficient. The firm therefore asked ABB Drives Alliance partner Slater Drive Systems (SDS) to help. SDS carried out an energy survey on R-Tek’s machines and then verified the results by loaning an ABB ACS 600, 160kW variable speed drive in combination with a Powermiser interface to the machine’s hydraulic system. Most injection moulding machines are hydraulically operated using electric motors to drive pumps that transfer oil from a sump and feed the pressurised oil to the moving parts of the machine. Under the control of the moulding machine’s computer, various directional valves are opened and closed at discrete points during a mould cycle. This process can be inefficient because the pump runs at a fixed speed, has a fixed capacity and so delivers a fixed amount of oil all the time. The machine rarely needs all the oil delivered and the excess is simply dumped back to the sump. At some points in the mould cycle, the machine can be wasting as much as 95% of the electrical energy supplied to the pump. Through tests performed on the machines operating under normal conditions, SDS found that the drive system (including the Powermiser interface) could save up to 40% of the energy consumption, resulting in a saving of £5,000 per machine per year. This equates to a payback of less than two years and an annual reduction in CO2 emissions of around 68 tonnes per machine. Bryan Simpson, quality assurance manager at R-Tek, comments: “The ABB drives have been operational for two months and we have been pleased both with their performance… The manufacturer of the electronic control system, Powermiser, has been back to review the system and has confirmed that we are getting the expected energy savings… We now want to do similar work on two other moulding machines, looking at how we can save energy on our compressors.”